Apparatus for puffing cereals



a. 7, 3 J. L. FERGUSON; 2,026,734

APPARATUS FOR PUFFING CEREALS Original Filed May 24, 1927 PEESSUEE 5552 val/z immm rq 26 Patented Jan. 7, 1936 Original application May .24, 1921, Serial No. 193,815. Divided and this application April 22,

1931, Serial N0. 531,939

8 Claims. (Cl. 99-2) My invention'relates to (method of pufllng cereal grains and an, apparatus for practicing the method hereinafter disclosed, the claims, pertaining to the, method being included in my co- '5 pending application Serial No. 193,815, filed May 24, 1927, and issued as Patent No. 1,839,917, January 5, 1932, of which the'present application is a division. v 1 I More particularly my invention relates to what may be termed a continuous pressure pufllng process. Heretofore grains have been puffed by enclosing the same lna chamber, raising the pressure in said chamber, and suddenly releasing the pressure by opening the enclosed chamber to the atmosphere or some other zone of lower pressure. Such an opening of the chamber functions to violently expel the grains within the chamber and upon their coming into the lower pressure zone they expand to several times their original size, thus forming a very nutritious and satisfactory edible cereal product, while maintaining at the same time, the general form of the original 'unpufied grains.

- My invention provides a method whereby one of the chief difliculties of the old system is eliminated. In all pufiing apparatus with which I am familiar, the grains'of cereal vary in size by reason of the fact that when the last grains are expelled from the chamber, the pressure in the latter has fallen so low that the grains do not properly puff or expand. In other words,.from

the moment of opening the chamber to the lower zone of pressure, there is a sharp decrease in the pressure from that existing before the chamber opened, to that of outside atmosphere. This results in a dwindling of the sizeof the grain as the pressure falls. My improved process overcomes this shortcoming by arranging ;to main-. tain a high pressure within the chamber until the last grains are expelled therefrom, said mainsented, I did not discover the same without mature experimentation. In other words, the unsatisfactory dwindling of the -size of the grains puffed was only a starting point and I have made many experiments in order to determine what was the cause of difficulty, and I am now. able to state that the sharp decrease in pressure is the reason therefor.

For a better understanding of my improved method of pufllng as well as an apparatus for practicing said method, reference should be had 5 to the accompanying drawing, in which drawing:

Figure 1 is an elevational view of an apparatus Ely means of which my invention may be pracced;

Figure 2 is a side elevational view taken at 10 to'that shown in Figure 1; and- Figure 3 is a fragmentary elevational view of one portion of theapparatus. 7

Referring now more particularly to the drawing, a chamber I0 is formed of heavy metal, or 5 equivalent material, sufliciently strong to withstand very high pressures which may be generated therewithin. The chamber 10 is mounted for rotation in standards ll-l I and may be constantly rotated to insure correct treatment of the 20 grains which are placed within the container or chamber it, such rotation being secured by ro-, tating a pulley l2. Of course a gear wheel and chain may be substituted for said pulley.

The chamber I0 ismore or less pear-shaped 25 having an aperture l3 at its lower end which is closed by a very quick opening valve l4, it being understood the same is. shown diagrammatically for purposes of illustration only, and may take any desired form so long as the practice of the 30 method hereinafter described and claimed is secured.

The chamber I0 is shown in Figs. 1 and 2 in a position which may be properly designated flr-' ing position, that is, the position in which the 35 same stands when the grains are expelled from the interior of the chamber. The upper end of the chamber lll'is provided with a closure valve 15 and a disconnecting member I8. By means of the member IS, the upper end of the chamber 40 ill may be connected through a pipe l1 and a valve 18 to a line l9 which leads to a reservoir of high pressure. a

For purposes of illustration only, I have shown a plurality of electrical resistor members 20 wrapped around the outer surface of the member l0, these resistors 20 deriving current from slip-rings 2l- -22 on which latter bear brushes 23-24 connected to leads 25 and 26 leading to anyzsuitable source or current such, for instance, 50 88 5 Assume now that a plurality of cereal grains are enclosed'within the chamber I, this being done by lifting an upper cover 28 secured to the upper end of the chamber"! by hinges 29 (the 2 s eaves valveiB being positioned permanently on said member 28).

The valve II is closed against high pressure as is also the valve i5 The elbow connection I1 is disconnected at 48 and swung aside so that= the chamber III is free to be slowly rotated in the "standards II, which rotation prevents the burning of thegrains which are contained within the chamber.

At thesame time the current passes through the resistors 20, and heats the surface of the chamber l and gradually raises the pressure within said chamber as the heat increases. Suit- "able indicating instruments, such asa gauge 30, may be placed anywhere upon thechamber Ill, wherefrom one will be able to observe the pressure existing within the chamber Hi. When this latter reaches a predetermined figure the rotation of the chamber I0 is stopped and the connection l'l made as shownin Fig. 1, and then the valve I4 is opened.

The sudden opening of the chamber to the at-- mosphere or, if desired, to some other zone of lower pressure, results in the grain being violently expelled through said opening it and upon their coming out into the low pressure zone, the

expansion of said grains takes place and a pull-- Such a maintenance of pressure is arranged by opening the valve I 5, either before or at the same time, as the valve 14 is opened. The pressure flows from the pressure reservoir through said ber at a predetermined figure so that there is not the sharp drop in pressure which results in a dwindling of the size of the grains. Thus .by the opening of the valves l4 and IS in proper sequence the desired results are obtained.

In Figure 3 I have illustrated an arrangement which I find to be very helpful in the practice of my improved pulling process. In this figure I show only a fragmentary section of the graincontaining chamber, but it is to be understood that a pipe 32 encircles the interior of the chamber and is connected to the valve l and pipe I! so that the pressure derived from the pressure reservoir is distributed from said pipe 32 through a number of very small apertures 33. Although the apertures "are so small that no grain may get therein during the rotation of the chamber III, the total area of said apertures is much in excess of the area of the aperture 13, for the reasons heretofore explained.

By so arranging the pipe 32 Just above the normal grain line 34, I am" enabled to assert a uniform pressure over a considerable area, thereby preventing the possibility of the pressure blowing through from the upper opening to the lower opening and as it were boring a hole in the grain to be pufled and nullifying the effect of maintaining the pressure in the upper part of the chamber I0. I

Moreover. theprovison of orifices 83 around the interior circumference of the chamber In produces a very desirable cleansing effect on the interior of the chamber and helps gravity feed the grains downwardly to the outlet.

As I have above intimated, the desirable maintenance of pressure in the chamber until all the grains pass through the lower aperture may also 5 be secured'without the introduction of pressure.

I find that the provision of a chamber in which the outlet orifice is at the lower portion thereof when in firing position, and of such shape, or

- otherwise so manipulated, that the grain stands inthe bottom thereof and over the exit opening prior to firing is of extreme advantage. The grains form a solid mass in the bottom portion 0! the chamber, and therefore, when the valve M is open the pressure cannot escape through 15 the mass of grains which are gravity propelled toward the orifice i3. Only a very small drop in pressure at a low rate of decrease is noticed with any close packing of the grains. In other words, the pressure is maintained within the chamber because the grains become clogged in the lower orifice and prevent the blowing out of the high pressure. As the pressure impels the grains outwardly, they are carried uniformly down and through the aperture I! to be expanded or pufled as they reach the outer lower zone of pressure.

I therefore regard the provision of means for practicing my method whereby the grains are gravity fed toward the outlet aperture of extreme importance and one of the desirable features of my invention.

Of course any other desired heating means than those shown may be used, for instance gas, but I have illustrated the electric resistor method as one which may be conveniently utilized. The

grains asthey emerge from the opening H are preferably directed into a large cage, or other similar compartment 3|, and are collected therefrom for disposal.

While I have heretofore described an appara- 40 tus in which the desirable pressure maintenance during the expulsion and pumng of the grains is accomplished by the actual addition of a medium under pressure to the interior of the heating chamber as the grains are passing therefrom, it 5 will of course be understood that this is but one example of means for maintaining the pressure as heretofore described and that other desirable means for maintaining the pressure therein may be utilized without departing from the spirit of the present invention, for instance the heating element shown may be used in this connection for raising the heat applied to the chamber as the grains pass therefrom, such raising of the temperature so increasing the pressure within the chamber that the same desirable pressure maintenance is obtained as has been previously described, or the metallic chamber or enclosing mass may be of such heat absorbent and emitting capacity that residual or stored-up heat is conthat the invention be limited only by the scope of the appended claims and the showing of the prior art.

I claim:

1. In an apparatus for pufllng grains, an enclosed chamber, means for raising the pressure in aoaavas said chamber, means for suddenly opening said chamber whereby the grains under pressure in said chamber are expelled therefrom and are thereby puffed, and means for insuring the existence of substantially the same pressure differential on the last grains expelled from said cham- I ber as on the first grains expelled therefrom.

2. In an apparatus for pulling grains, an en-' closed chamber, means for raising the pressure thereby puffed, a

in said chamber, means for suddenly opening said chamber whereby the grains under pressure in said chamber are expelled therefrom and arethereby pulled, and means connecting said chambe to a source of pressure during the. time the said chamber is open and maintaining the same pressure diflerential on the last grains expelled from said chamber as on the first grains expelled therefrom.

3. In an apparatus for pufflng grains, an enclosed chamber, means for raising the pressure in said chamber, means for suddenly opening said chamber whereby the grains under pressure in said chamber are expelled therefrom and are thereby pufled, and means for simultaneously connecting said chamberto a source of pressure when said chamber is opened thereby for insuring the existence of substantially the same pressure differential on the last grains expelled from said chamber as on the first grains expelled therefrom.

4. In an apparatus for pufllng grains, an enclosed chamber, means for raising the pressure in saidchamber, means for suddenly opening said chamber whereby the grains under pressure in;

said chamber are expelled therefrom and are pressure reservoir capable of supplying throughout the period of expulsion of said grains from saidchamber a pressure atleast as high as the pressure in said chamber Just prior to the opening thereof, and means for connecting said chamber to said reservoir when the chamber is open and the grains are being expelled to insure the existence of substantially. the same pressure diflerentiai on the last grains expelled from said chamber as on the first grains expelled therefrom. a v

5. In an apparatus for pulling grains, an enclosed chamber having an exit opening therein. means for raising the pressure within said chamber thereby to prepare said grains for expulsion into a zone of the lower pressure to putt the same, said chamber having walls converging towards the opening through which said grains are expelled to form a dam restricting the flow of grain through said opening to retain substantially the chamber to prevent the scorching-of the grains same pressure differential on the last grains expelled-from said chamber as on the first grains expelled therefrom. whereby the grains themselves prevent substantially the reductiorbof the interior pressure. g

6. In an apparatus for pulling grains, an enclosed chamber having an opening therein through which grainaare expelled," means for raising the pressure within said chamber thereby to prepare said grains for expulsion into a zone of the lower pressure to puff the same, and pressure maintenance means through which the pressure in the interior of said chamber may be maintained at a desirable figure during the expulsion of said grains, said pressure maintenance means ll comprising structure comprehending a plurality of openings, each of which is small enough to prevent the clogging thereof by the grains, but the combined area of which is greater than the opening through which said grains are expelled. 20

'Z. In an apparatus for putting grains, an enclosed chamber, means for raising the pressure within said. chamber thereby to prepare said grains for expulsion into av zone of the'iower pressure to puff the same, said chamber being so 25 shaped that the grains being expelled function to maintain the high pressure within said chamber as said grains are expelled therefrom, and means including heating elements for maintaining substantiaily the same pressure differential on the 3 last grains expelled from said chamber ason the first grains expelled therefrom.

8. In an apparatus for puillng grains, an enclosed chamber, means for raising the pressure within said chamber thereby to prepare said grains for expulsion into a zone of the'lower pressure to puff the same, said means applying heat to said chamber to increase the pressure therein, and means permitting. the movement of said therewithin, said chamber being provided with an opening toward which latter the walls of said chamber converge, and said movement-permitting means being such as to permit the said chamber to be brought into position during the expulsion of said grains so that the said grains are gravityactuated toward the opening at the apex of said converging portion to block the opening during grain expulsion and thereby maintain substantially the same pressure differential on the last 50 grains expelled from said chamber as on the first grains expelled therefrom.

John L. FERGUSON. 

